Alongside quantitative evidence on the effects of healthcare interventions, it's important to have qualitative evidence on people's views about these interventions, particularly if they are delivered at the population level. This is the case with mass drug administration for filariasis, which is a parasitic disease that can result in swollen limbs and disability and, in February 2022, the Cochrane Infectious Diseases group, based at the Liverpool School of Tropical Medicine in the UK, published a qualitative evidence synthesis on community views about this intervention.

Mass drug administration, or MDA, involves the regular delivery of medicines to whole populations, regardless of whether an individual has the disease or not. It aims to prevent those infected from passing the disease on to others in the community and is more cost effective than diagnosing and treating on an individual basis. The World Health Organization recommends this approach for a number of diseases such as malaria and lymphatic filariasis in low- and middle-income countries.
However, for governments and their health services, MDA is a large logistical task requiring money and staff, and success depends on whether communities are willing to take the medicines given. 
In this review, the authors included 29 qualitative studies that explored how people view and experience these programmes. Although most of the studies were conducted in India, a broad range of countries in Africa, South‐East Asia, and South America were covered, and four themes emerged:
Firstly, people weigh up many benefits and harms before participating in a MDA programme. They understand that the medicine can reduce the suffering, stigma, and costs of developing the disease; but these benefits do not always mesh with their experiences. In particular, side effects are frightening and unwelcome; and are amplified through rumor and social media, creating anxiety in some communities.
Next, although some people may have unwavering faith in their government and therefore the MDA programme, many people are suspicious of these programmes. When people lack a detailed explanation for why they should participate, or have unexpected experiences, such as side effects, they often develop explanations based on the historical backdrop and level of trust they have in relevant authority figures.
Next, MDA programmes expect compliance, and this can become coercive and blaming. Health workers and community members may stigmatize non‐compliance, which can become coercive, and communities may appear to comply publicly, but privately reject treatment.
Finally, the review authors found that those distributing drugs, which are typically community members themselves, without formal qualifications, are often not respected or valued. They have little authority and the behavior of some damages the MDA programme's reputation. People want information about the programmes to help decide about participation, but the drug distributors are not sufficiently informed, or skilled in this communication.

In conclusion, this Cochrane qualitative evidence synthesis found generally high certainty evidence that the decision to take part in MDA programmes for filariasis is influenced by individual direct experience of benefit and harm; social influences in the community; political influences and their relationship to government; and historical influences. Fear of side effects was common and this appears to be particularly important for communities. The Cochrane authors were also surprised at the strength of feeling expressed when views were negative and they call for more debate about the enthusiasm for MDA schemes in the light of their review, which can be found at Cochrane Library dot com with a simple search for 'mass drug administration for filariasis'.